Non-volatile memory is memory that retains stored data when power is disconnected from the system. Examples of non-volatile memory include Phase-Change Memory (PCM) and flash memory. Phase Change Memory (PCM) is a promising technology for building main memory systems. A prominent characteristic of PCM is that its write latency is much greater than its read latency. Servicing these relatively slow writes causes significant contention for read requests. For a baseline PCM system, the slow writes increase the effective read latency by almost two times, causing significant performance degradation.